#include<stdio.h>
double Func(double x,double y);
int main(void)
{   double a=100.0,b,sD;
    scanf("%lf",&b);
    sD=Func(a,b);
    printf("%lf",sD);
    return 0; 
 } 
 double Func(double x,double y)
 {double z;
  z=(x+y)*(x-y);
  return z;
 }
 
